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OutlineOutline of the report of the report

INTRODUCTIONINTRODUCTION

CR superconducting magnet-Magnetic field DesignCR superconducting magnet-Magnetic field Design

Superconducting Coil DesignSuperconducting Coil Design

Conductor designConductor design

Magnetic field in superconducting coilsMagnetic field in superconducting coils

Quench propertiesQuench properties

Stress analysis of superconducting coils Stress analysis of superconducting coils

Design of Cryostat for Collector Ring coilsDesign of Cryostat for Collector Ring coils

Configuration of CryostatConfiguration of Cryostat

Cooling Way of Superconducting magnetCooling Way of Superconducting magnet

Stress analysis for Cryostat and coil supportStress analysis for Cryostat and coil support

Conclusions Conclusions

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INTRODUCTIONINTRODUCTION for Layout of the collector Ring (CR)Layout of the collector Ring (CR)

CR magnetCR magnet

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Design Requirements for CR DipoleDesign Requirements for CR Dipole

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Benchmark and Benchmark and raodmap for CRraodmap for CR The CR dipole magnets : superferric H-type with a large available aperture (140

×380 mm2).

Their useful maximum magnetic field : 1.6T.

The R&D work for the CR dipole magnet system:

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Preliminary Design Preliminary Design of raodmap for CRof raodmap for CR Electromagnetic design : Yoke, pole and coils parameters, Electromagnetic design : Yoke, pole and coils parameters,

window, coils structure and typewindow, coils structure and type

Yoke and pole configuration and material, fabrication

Superconducting coils and CryogenicSuperconducting coils and Cryogenic

Conductor Design, Operating Current : Operating Current Choice Conductor Design, Operating Current : Operating Current Choice from Temperature Margin Point, Operating Current Choice from from Temperature Margin Point, Operating Current Choice from Mechanical Consideration, Dimensions Optimization, Mechanical Consideration, Dimensions Optimization, Configuration Choice, Force Interaction, Mechanical Configuration Choice, Force Interaction, Mechanical Considerations, Spatial Field Distribution, Manufacturing Route Considerations, Spatial Field Distribution, Manufacturing Route Winding, Insulating, Impregnation,Joints and Terminations, Winding, Insulating, Impregnation,Joints and Terminations, Instrumentation, Assembly

Power Supply, Quench Detection and Protection Systems

CR Main Instrumentation, CR Main Quality & Assurance Procedures

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Intermediate Design Intermediate Design of raodmap for CR-1of raodmap for CR-1

Thermal Analysis: Temperature Margin Calculation

Pressure Rise Inside the Cryostat During Quench

technology risk analysis, Analysis & Conclusions,

Quench Protection: Protection Principle, single and series

Protection Scheme Analysis, detection, instrument

Spatial Field Distribution at mechanical error

Structural Analysis: Structural Evaluation, Model Description and Criteria

Standard Model, Advanced Model, Helium vessel

Equivalent Stresses, Cool Down Stresses

Conductor Quench Stresses

Deformed State, Shear Stresses, friction

Cryogenic Scheme : Cryogenic Operating Requirements,Steady State Load

Refrigeration Load, Ring cryogenic system

Cryogenic Losses :Thermal Radiation, Current Leads

Supports, Cool Down, Normal Operation

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Intermediate Design Intermediate Design of raodmap for CR-2of raodmap for CR-2

Winding Scheme: Requirements, Spool Mounting Vehicle, Conductor Cleaning,

Bending Process, Coil Winding Jig, Epoxy, Turn Table

Winding Fastening Units, Layer Transition

Turn-to-turn and Layer-to-layer Spacer Insertion

Conductor Forming for Coil, Termination, System Control,

Insulation test, RT and CT.

Yoke and Pole : Yoke material, Yoke punching and error control, size

Yoke assembly, yoke connect with cryogenic system,

Yoke adjustment and field quality.

System test : Test flow chart....................

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To be continuous hard work To be continuous hard work

and breakthroughand breakthrough

..... ........... ......

CR Final DesignCR Final Design

CR Engineering DesignCR Engineering Design

CR Fabrication, Installation & Testing.CR Fabrication, Installation & Testing.

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Collector Ring superconducting magnetCollector Ring superconducting magnet

Magnetic field calculationMagnetic field calculation

with 2 D OPERA2Dwith 2 D OPERA2D

3D ANSYS3D ANSYS

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Main parameters of the CR dipole magnetMain parameters of the CR dipole magnet

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Cross section of the CR dipole magnet for warm and colCross section of the CR dipole magnet for warm and cold pole, with separated and connected pole and yoked pole, with separated and connected pole and yoke

Version -1 Version -2

Version -3 Version -4

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Main design parameters for four versionsMain design parameters for four versionsMain parameters Version 1 Version 2 Version 3 Version 4

Total width of Magnet (m) 2.25 2.20 2.04 2.21

height of the yoke (m) 1.34 1.34 1.24 1.22

width of the pole (m) 0.98 0.98 0.84 0.86

height of pole (m) 0.85 0.85 0.85 0.85

air gap between yoke and pole (mm)

25 – 32 40-47 No No

available width of gap (mm) 140 140 140 140

coil cross section (mm2) 50×45 50×50 45×60 45×60

maximum current density ( A/mm2) 69 A/mm2 69 A/mm2 50 A/mm2 50 A/mm2

Available area for beam line (mm2) ±70 × ±225 ±70 × ±225 ±70 × ±190 ±70 × ±190

a 65 65 65 65

b 60 60 65 65

c 40 45 45 45

d 55 55 40 30

Cool structure for yoke and pole warm yoke and pole

warm yoke and cool pole

warm laminated yoke and pole

warm yoke laminated and pole

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Flux density distribution along the border Flux density distribution along the border of the elliptical good field area-2Dof the elliptical good field area-2D

B/BB/B

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Flux density distribution 3DFlux density distribution 3D

Trapezoidal-shaped coilTrapezoidal-shaped coil

D-shaped coilD-shaped coil

Double arcDouble arc

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Comparison with coil structure and further job

It needs: optimize slot size and placement in CR with 3D, three It needs: optimize slot size and placement in CR with 3D, three dimensional magnetic field calculations to check the saturation dimensional magnetic field calculations to check the saturation region, closer look at end design with superferric magnets, region, closer look at end design with superferric magnets, closer look at effects of allowed error terms in influence on the closer look at effects of allowed error terms in influence on the field quality, study lamination fabrication of coil-shaped.field quality, study lamination fabrication of coil-shaped.

Based on OPER3D-magnetic field analysisBased on OPER3D-magnetic field analysis

Therefore, from view of field distribution, the double-arc coil is Therefore, from view of field distribution, the double-arc coil is the best field quality, the next is the best field quality, the next is DD-shaped coils. The trapezoidal--shaped coils. The trapezoidal-shaped coil is the worst. From the view of manufacture process, shaped coil is the worst. From the view of manufacture process, the the DD shaped coils and trapezoidal coil seems are easily to be shaped coils and trapezoidal coil seems are easily to be fabricated. The double-arc coil with the weight of fabricated. The double-arc coil with the weight of superconducting wire and size of magnet is the smallest.superconducting wire and size of magnet is the smallest.

Take the cold pole as former of superconducting Take the cold pole as former of superconducting coils.coils.

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Superconducting coils for CR

Selection of wire and cableSelection of wire and cable Magnetic field in superconducting coilsMagnetic field in superconducting coils Lorentz force and Mechanical stressLorentz force and Mechanical stress Quench Detection and protectionQuench Detection and protection

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Design of Conductor Design of Conductor BenchmarkBenchmark

This leads to the design choice of a superferric magnet with warm iron with the minimum cold mass option, it remarkably reduces the cool down time for superconducting magnet system and potted with epoxy resin in the wetting winding technique or vacuum-impregnated technology,

The conductor with low operating current, type 150-300 A, wound with high Cu/SC ratio superconducting monolith NbTi/Cu wire.

For large-scale superconducting coils, the design of superconducting coils should be cryogenic stability, with large margin and lower hot-spot temperature and voltage during quench.

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Magnetic field distribution in Magnetic field distribution in superconducting cross-sectional (a) superconducting cross-sectional (a)

and coils (b)-and coils (b)-version4version4

BBmaxmax = 1.15 T, 2D can not obtain the maximun = 1.15 T, 2D can not obtain the maximun field in endfield in end

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Magnetic field distribution in Magnetic field distribution in superconducting cross-sectional area-3D-superconducting cross-sectional area-3D-

Trapezoid-shaped Trapezoid-shaped version3version3

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B in D-shaped superconducting B in D-shaped superconducting coilscoils

Bmax=1.425 T

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B in Double arc-shaped coilsB in Double arc-shaped coils

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Max. Operating Field of 2 T

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Cryogenic stability conductorCryogenic stability conductorGood Choice for large-scale SC magnetGood Choice for large-scale SC magnet

Cryogenic stable conductors cooled by pool boiling helium are Cryogenic stable conductors cooled by pool boiling helium are advantageous for high field magnets in a large diameter advantageous for high field magnets in a large diameter operating in the high current density with a modest ramp rate.operating in the high current density with a modest ramp rate.

The method is with high reliability, simple cooling arrangements The method is with high reliability, simple cooling arrangements and low cost at the expense of low current density in the and low cost at the expense of low current density in the winding. winding.

The cryogenic stable methods imply that any normal zone The cryogenic stable methods imply that any normal zone should recover after any disturbance.should recover after any disturbance.

If we select the operating temperature for superconducting coils If we select the operating temperature for superconducting coils of 4.2 K, NbTi/Cu monolithic conductor with high Cu/non copper of 4.2 K, NbTi/Cu monolithic conductor with high Cu/non copper ratio with 5-10 is suitable.ratio with 5-10 is suitable.

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Technical Details

Number of filaments 40-600

Cu/Sc ratio 8-10.0

Wire dimensions (bare) 0.85 x 1.9 mm

Insulated

Filamentary dia.

1.0 x 2. 0 mm+/- 0.010 mm

20-70 m

Proposed NbTi/Cu monolithic conductorProposed NbTi/Cu monolithic conductor

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Structure for Superconducting Coils

Racetrack shape D shape

Double-straight line

Trapezoidal

Compensation coils

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Main design parameters for the coilsMain design parameters for the coils

Conductor of NbTi/Cu Include the insulator, 0.95-1.0 mm×2.0 mm

Bare wire of NbTi/Cu : 0.85 mm ×1.9 mm

Consideration of layer insulator 200-300 m

Cu/SC = 9 or 10.0, RRR> 100,

Coils cross-sectional area 45 mm × 60 mm

Total turn in each coils 30 turns × 36 layers

Operating current 175.0 A (70A/mm2) filling factor=0.646

Center field 0.8-1.6 T

Cooled way Pool cooling with liquid helium

operating current to its critical current

< 13 %

Quench simulation with sub. Maximum temperature lower than 100 K

Mechanics stress Helium container to supporter

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Main suggest for the superconducting coilsMain suggest for the superconducting coils

Decreased the cross-sectional area of Coil Decreased the cross-sectional area of Coil

from 45 from 45 × 60 mm× 60 mm22 to to 30 30 × 50 mm× 50 mm22,,

Increased the operating current for Increased the operating current for superconducting coils, and operating current superconducting coils, and operating current to its critical current ratio Ito its critical current ratio Ioptopt/I/Icc = 20-30 % , = 20-30 % ,

Used the cold pole as the superconducting Used the cold pole as the superconducting coil former to support the Lorentz force and coil former to support the Lorentz force and reduce the displacement in straight section.reduce the displacement in straight section.

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Superconducting magnet Quench detection and Superconducting magnet Quench detection and protection circuit protection circuit

DC

Power Supply

Diode

Upper coil Lower coil

Switch

Resitor

DC

Power Supply

Diode

Upper coil Lower coil

Switch

Resitor Diode ResitorDC

Power Supply

Upper coil Lower coil

Switch

ResitorResitor

Amplifier

Type-AType-A

Type-BType-B

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Position of quench origin for hot spot temperature Position of quench origin for hot spot temperature calculationcalculation

Different scenarios

Cross section of the winding

Cross section of the winding

Quench origin

Quench origin

Case I Case II

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Model of normal zone propagationModel of normal zone propagation

Normal zone shaped Superconducting coils structure

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Results for circuit-AResults for circuit-A

Dump Resistance (ohm)Dump Resistance (ohm) 1.01.0 1.51.5 2.02.0 2.52.5 3.03.0

TTmaxmax 90.090.0 84.884.8 79.779.7 74.774.7 70.070.0

EEdump(%)dump(%) 31.631.6 44.344.3 55.055.0 63.963.9 71.071.0

VVmaxmax 306306 281281 372372 465465 558558

Results for circuit-BResults for circuit-BDump Resistance (ohm)Dump Resistance (ohm) 1.01.0 1.51.5 2.02.0 2.52.5 3.03.0

TTmaxmax 60.560.5 60.460.4 59.959.9 58.958.9 57.457.4

EEdump(%)dump(%) 80.080.0 82.982.9 83.783.7 85.485.4 86.286.2

VVmaxmax 186186 279279 372372 465465 557557

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Cryostat for Collector Ring coilsCryostat for Collector Ring coils

Configuration of CryostatConfiguration of Cryostat

Cooling Way of Superconducting magnetCooling Way of Superconducting magnet

Stress analysis for CryostatStress analysis for Cryostat

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Design parameters for CR magnetDesign parameters for CR magnet

• 85 mm - 70 mm = 15 mm• Cryostat space is limitation width_1 = 590 mm-530 mm = 60 mm width_2 = 470-420 mm = 50 mm height_1 = 180 mm - 135 mm= 45 mm height_2= 90mm• coil size width = (530mm-470 mm) =60 mm height = (170mm-110mm) = 45 mm

•Cryostat space is limitation width_1 = 590 mm-530 mm = 60 mm width_2 = 470-420 mm = 50 mm height_1 = 180 mm - 135 mm= 45 mm height_2 = 110mm•

coil size

width = (530mm-470 mm)

=60 mm

height = (170mm-110mm)

= 45 mm

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•Vacuum vessel, external supports, and compact structure.

•Thermal radiation shields and intermediate temperature intercepts with LN2 heat exchanger.

•Multi-layer super-insulation system for thermal radiation.

•Suspension and anchor systems with G10.

•Cryogenic piping for cooling system.

•Cold mass end domes

•Detailed stress analysis for helium vessel and coils.

•Interconnecting bellows, shield bridges, and vacuum relief devices.

Scope of the cryostat design and production effortScope of the cryostat design and production effort

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Cool way for the CR-Superconducting magnetCool way for the CR-Superconducting magnet

Pool cooling way for the coils

Insulation vacuum, thermal shields, HTSC Current lead etc.

No LN2 vessel needed, instead of heat exchanger.

Forced flow, He gas and LN2 for Radiation shield Beam pipe

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Main structure of the cryostatMain structure of the cryostatThe cryostat consists of D or Trapezoidal coils, stainless bobbin that serves as the main structural support and as the helium vessel about 12-16 structural support and link from 300 K to 4K, a nitrogen shield and a vacuum vessel.

The satellite cryostat provides all the connections between the superconducting coils and outside world including: cryogenic supply, return and storage, pressure relief instrumentation and current leads.

Using thermal exchanged structure to force flow LN2 to cool down the thermal radiation shield to reduce the space.Cooled helium gas can be used to cool the vacuum tube.

Cryostat consist of two main sub-assemblies;1)A magnet cryostat housing the superconducting coil2)Satellite cryostat with cryogenic reservoirs3)Connections to outside world

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Liquid Helium vessel systemLiquid Helium vessel systemLHe vessel is satellite cryostat and LHe vessel with contain coil ,

LHe vessel should be designed according to the strength, stiffness and stability.

A stiffening plate with rectangular hole will be placed LHe vessel ,

The outer surface of helium vessel will be wrapped with 15-20 multi-layered super-insulation,

Used for the outer supporter for superconducting coils

Adjustment of the position and direction for coils.

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Calculated heat loads of LHe and Thermal shieldCalculated heat loads of LHe and Thermal shield

To LHe vessel(4.2K) to Thermal shield(80K)To LHe vessel(4.2K) to Thermal shield(80K)

heat conductionheat conduction

vertical support 66.4mW 644mWvertical support 66.4mW 644mW

horizontal adjuster 48.5mW 351mWhorizontal adjuster 48.5mW 351mW

radiation 532mW 16.61Wradiation 532mW 16.61W

Heat conduction Heat conduction

of LHe neck tube 37.98 mW 1.28Wof LHe neck tube 37.98 mW 1.28W

total 682.18mW 18.88total 682.18mW 18.88

boif-off rate 0.96l/hr 0.419l/hrboif-off rate 0.96l/hr 0.419l/hr

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FEM ANYLYSIS FOR main component partsFEM ANYLYSIS FOR main component partsinternal pressure to outer shell of LHe vessel(5atm)

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Assembly processing for CR coils and yokeAssembly processing for CR coils and yoke

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Stress analysis in Cryostat and superconductStress analysis in Cryostat and superconducting coilsing coils

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Survey material properties forSurvey material properties for 316,304L and the other structure 316,304L and the other structure

materialmaterial

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Structural Design Criteria

Design Tresca stress values (Sm) Sm : Minimum values of [2/3 Sy & 1/2 Su]where, Sy is 0.2% offset yield stress & Su is ultimate strength

Stress allowable limits Primary membrane stress Pm 1.0 K Sm Primary membrane + bending stress Pm+Pb 1.3 K Sm Primary + secondary stress Pm+Pb+Q 1.5 K Smwhere, K depends on operating condition, plate thickness, and welding

Fracture toughness limits Normal operation Km 0.67 KIC Anticipated upset operation Km 0.83 KIC Faulted operation Km 0.91 KIC

Static Stress Limits of Metallic Materials

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Stress Limits of Non-Metallic Materials

Insulation materials of SC coilsTurn insulation : Kapton + S-glass + VPI Ground wrap insulation : S-glass + VPI

Shear stress allowable S = 0.5 0 +C2 Sc(n)

Where, 0 : pure shear bonding strength - In KSTAR, design value of 0 is 50 MPa for fatigue cycles.

- As a case study, the lower value of 30 MPa has will be used.

C2 : Slope of shear and compressive strength Sc(n) : Applied compressive stress

0, C2 : Experimental data

Normal tensile stress allowable Sn 1 MPa

Structural Design Criteria

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Fatigue Evaluation of Metallic Materials

Two approach on fatigue evaluation Stress-life curve evaluation : No defect assumption Crack growth assessment : based on linear elastic fracture mechanics

Stress-life (S-N) curve evaluation Mean stress effect Cumulative damage (Miner’s rule) Variable amplitude cyclic stress

Fatigue crack growth (da/dN) assessment Initial crack type

Semi-elliptical surface crack Elliptical embedded crack

Mean stress effect : Modified Paris’ equation

Safety factor(SF) : Design fatigue life (2) 100,000 cycles

00

0)(

)1( )1(0 mmm KCK

R

C

dN

da

cyclemC / 10243.1 130

0.29 ,45.30 m

Structural Design Criteria

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Main stress analysis of Main stress analysis of Trapezoid-shaped coils used Trapezoid-shaped coils used

model amd meshmodel amd mesh

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Main stress analysis of Trapezoid-Main stress analysis of Trapezoid-shaped coilsshaped coils

Used 10 mm thickness of helium vessel

Maximum Von-Misses Stress 61.3MPa, Displacement =5.98 mm Maximum Von-Misses Stress 61.3MPa, Displacement =5.98 mm

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Displacement of coils in X,Y and ZDisplacement of coils in X,Y and Z

3.956 mm

1.449mm

0.311mm

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Stress of coils in X,Y and ZStress of coils in X,Y and Z

48.3MPa 39.3MPa

20.0MPa

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Strain of coil in X,Y and ZStrain of coil in X,Y and Z

0.2338%

0.1005%

0.1828%

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D-Shaped superconducting 3D modelD-Shaped superconducting 3D model

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Cryostat for SuperFRS magnet system Cryostat for SuperFRS magnet system Main structure of the cryostatMain structure of the cryostat

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Main structure of the cryostatMain structure of the cryostat

cryostat

yoke

Pole tips

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Superconducting dipole coils for SuperFRSSuperconducting dipole coils for SuperFRS

Liquid Helium cryostat for Liquid Helium cryostat for SFRS systemSFRS system

Thermal shield systemThermal shield system

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Comparison of Cryogenic Sensor for CR

Sensitivity (K-1)

(dR/RdT)

Accuracy (mK) Thermometry

Temperature

Range (K) at 4.2 K at 77 K at 4.2 K at 77 K

Comment on High B-

Field

( ~10 T )

Germanium 1.4~100 1 0.1 10 20 Improper

Rhodium-iron 1.4~500 0.1 0.1 30 30 Improper

Carbon 1.4~100 1 0.1 50 100 Moderate

Carbon Glass 1.4~300 1 0.1 30 30 Excellent

Silicon diode 2~300 10 1 30 300 Improper

Au/Fe-chromel

Thermocouple

1.4~500 100 10 500 500 Moderate

CLTS (Cryogenic

Linear Temperature

Sensor)

1.5~300 1 0.1 30 30 Improper

Platinuim 50~500 - 0.01 - 300 Excellent

Cernox 0.3~325 0.01 0.001 5 50 Excellent

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Conclusions Conclusions Based on OPER3D-magnetic field analysis, optimize slot size Based on OPER3D-magnetic field analysis, optimize slot size

and placement in CR with 3D, and placement in CR with 3D,

Take the cold pole as former of superconducting coils.Take the cold pole as former of superconducting coils.

Decreased the cross-sectional area of Coil, Increased the Decreased the cross-sectional area of Coil, Increased the operating current.operating current.

Detailed mechanical and thermal stress analysis for superconDetailed mechanical and thermal stress analysis for superconducting coils and helium vessel to check the outer support and ducting coils and helium vessel to check the outer support and thickness of wall. Cryostat design and analysisthickness of wall. Cryostat design and analysis

Subdivision protection is suitable for the Single magnet.Subdivision protection is suitable for the Single magnet.

Instrument interface. Instrument interface.

Superconducting coils operating and fabricating technology.Superconducting coils operating and fabricating technology.

R &D experiment and test should be executed.R &D experiment and test should be executed.